#include <stdio.h>
#include <stdlib.h>

#include "defs.h"

action **parser;
int SRtotal;
int RRtotal;
short *SRconflicts;
short *RRconflicts;
short *defred;
short *rules_used;
short nunused;
short final_state;

static int SRcount;
static int RRcount;

extern action *parse_actions();
extern action *get_shifts();
extern action *add_reductions();
extern action *add_reduce();


void make_parser(void)
{
int i;
  parser = NEW2(nstates, action *);
  for (i = 0; i < nstates; i++)
   	parser[i] = parse_actions(i);

  find_final_state();
  remove_conflicts();
  unused_rules();
  if (SRtotal + RRtotal > 0) total_conflicts();
  defreds();
}


action *parse_actions(int stateno)
{
action *actions;

  actions = get_shifts(stateno);
  actions = add_reductions(stateno, actions);
  return (actions);
}


action *get_shifts(int stateno)
{
action *actions, *temp;
shifts *sp;
short *to_state;
int i, k;
int symbol;
  actions = 0;
  sp = shift_table[stateno];
  if (sp)
    {
	 to_state = sp->shift;
	 for (i = sp->nshifts - 1; i >= 0; i--)
    	{
	    k = to_state[i];
	    symbol = accessing_symbol[k];
	    if (ISTOKEN(symbol))
	    {
		temp = NEW(action);
		temp->next = actions;
		temp->symbol = symbol;
		temp->number = k;
		temp->prec = symbol_prec[symbol];
		temp->action_code = SHIFT;
		temp->assoc = symbol_assoc[symbol];
		actions = temp;
	    }
	  }
    }
  return (actions);
}

action *add_reductions(int stateno,action *actions)
{
int i, j, m, n;
int ruleno, tokensetsize;
unsigned *rowp;
  tokensetsize = WORDSIZE(ntokens);
  m = lookaheads[stateno];
  n = lookaheads[stateno + 1];
  for (i = m; i < n; i++)
    {
    ruleno = LAruleno[i];
	 rowp = LA + i * tokensetsize;
	 for (j = ntokens - 1; j >= 0; j--)
	   {
	   if (BIT(rowp, j))
		  actions = add_reduce(actions, ruleno, j);
	   }
    }
  return (actions);
}


action *add_reduce(action *actions,int ruleno,int symbol)
{
action *temp, *prev, *next;
  prev = 0;
  for (next = actions; next && next->symbol < symbol; next = next->next)
	 prev = next;
  while (next && next->symbol == symbol && next->action_code == SHIFT)
    {
	 prev = next;
	 next = next->next;
    }
  while (next && next->symbol == symbol &&
	    next->action_code == REDUCE && next->number < ruleno)
    {
	 prev = next;
	 next = next->next;
    }
  temp = NEW(action);
  temp->next = next;
  temp->symbol = symbol;
  temp->number = ruleno;
  temp->prec = rprec[ruleno];
  temp->action_code = REDUCE;
  temp->assoc = rassoc[ruleno];
  if (prev)
    prev->next = temp;
  else
	 actions = temp;
  return (actions);
}


void find_final_state(void)
{
int goal, i;
short *to_state;
shifts *p;

    p = shift_table[0];
    to_state = p->shift;
    goal = ritem[1];
    for (i = p->nshifts - 1; i >= 0; --i)
    {
	final_state = to_state[i];
	if (accessing_symbol[final_state] == goal) break;
    }
}


void unused_rules(void)
{
int i;
action *p;

    rules_used = (short *) allocate(nrules*sizeof(short));
    if (rules_used == 0) no_space();

    for (i = 0; i < nrules; ++i)
	rules_used[i] = 0;

    for (i = 0; i < nstates; ++i)
    {
	for (p = parser[i]; p; p = p->next)
	{
	    if (p->action_code == REDUCE && p->suppressed == 0)
		rules_used[p->number] = 1;
	}
    }

    nunused = 0;
    for (i = 3; i < nrules; ++i)
	if (!rules_used[i]) ++nunused;

    if (nunused)
	if (nunused == 1)
	    fprintf(stderr, "%s: 1 rule never reduced\n", myname);
	else
	    fprintf(stderr, "%s: %d rules never reduced\n", myname, nunused);
}


void remove_conflicts(void)
{
    register int i;
    register int symbol;
    register action *p, *pref;

    SRtotal = 0;
    RRtotal = 0;
    SRconflicts = NEW2(nstates, short);
    RRconflicts = NEW2(nstates, short);
    for (i = 0; i < nstates; i++)
    {
	SRcount = 0;
	RRcount = 0;
	symbol = -1;
	for (p = parser[i]; p; p = p->next)
	{
	    if (p->symbol != symbol)
	    {
		pref = p;
		symbol = p->symbol;
	    }
	    else if (i == final_state && symbol == 0)
	    {
		SRcount++;
		p->suppressed = 1;
	    }
	    else if (pref->action_code == SHIFT)
	    {
		if (pref->prec > 0 && p->prec > 0)
		{
		    if (pref->prec < p->prec)
		    {
			pref->suppressed = 2;
			pref = p;
		    }
		    else if (pref->prec > p->prec)
		    {
			p->suppressed = 2;
		    }
		    else if (pref->assoc == LEFT)
		    {
			pref->suppressed = 2;
			pref = p;
		    }
		    else if (pref->assoc == RIGHT)
		    {
			p->suppressed = 2;
		    }
		    else
		    {
			pref->suppressed = 2;
			p->suppressed = 2;
		    }
		}
		else
		{
		    SRcount++;
		    p->suppressed = 1;
		}
	    }
	    else
	    {
		RRcount++;
		p->suppressed = 1;
	    }
	}
	SRtotal += SRcount;
	RRtotal += RRcount;
	SRconflicts[i] = SRcount;
	RRconflicts[i] = RRcount;
    }
}


void total_conflicts(void)
{
   fprintf(stderr, "%s: ", myname);
   if (SRtotal == 1)
	  fprintf(stderr, "1 shift/reduce conflict");
   else if (SRtotal > 1)
	  fprintf(stderr, "%d shift/reduce conflicts", SRtotal);
   if (SRtotal && RRtotal)
	  fprintf(stderr, ", ");
   if (RRtotal == 1)
	  fprintf(stderr, "1 reduce/reduce conflict");
   else if (RRtotal > 1)
	  fprintf(stderr, "%d reduce/reduce conflicts", RRtotal);
   fprintf(stderr, ".\n");
}


int sole_reduction(int stateno)
{
int count, ruleno;
action *p;

  count = 0;
  ruleno = 0;
  for (p = parser[stateno]; p; p = p->next)
    {
	 if (p->action_code == SHIFT && p->suppressed == 0)
	   return (0);
	 else if (p->action_code == REDUCE && p->suppressed == 0)
	   {
	   if (ruleno > 0 && p->number != ruleno)
		  return (0);
      if (p->symbol != 1)
		  ++count;
      ruleno = p->number;
	   }
    }
  if (count == 0)
	 return (0);
  return (ruleno);
}


void defreds(void)
{
int i;
    defred = NEW2(nstates, short);
    for (i = 0; i < nstates; i++)
	defred[i] = sole_reduction(i);
}
 
void free_action_row(action *p)
{
action *q;
  while (p)
    {
      q = p->next;
      FREE(p);
      p = q;
    }
}

void free_parser(void)
{
int i;

  for (i = 0; i < nstates; i++)
    free_action_row(parser[i]);
  FREE(parser);
}


